Centrifugal Test on Behavior of the Dolphin Structure under Ship Collision

선박충돌 시 돌핀 구조물의 거동에 대한 원심모형실험

  • Oh, SeungTak ;
  • Bae, WooSeok ;
  • Cho, SungMin ;
  • Heo, Yol
  • 오승탁 (충북대학교 대학원 토목공학과) ;
  • 배우석 ((주)나노지오이엔씨 기술연구소) ;
  • 조성민 (한국도로공사 도로교통기술원) ;
  • 허열 (충북대학교 토목공학과)
  • Received : 2010.10.08
  • Accepted : 2010.12.07
  • Published : 2011.01.01

Abstract

The impact protection system consists of an arrangement of circular sheet pile cofferdams-denoted dolphin structuredeeply embedded in the seabed, filled with crushed rock and closed at the top with a robust concrete cap. Centrifuge model tests were performed to investigation the behaviors of dolphins in this study. Total 7 quasi-model tests and 11 dynamic model tests were performed. The main experimental results can be summarized as follows. Firstly, The experimental force-displacement results for quasi-static tests show a limited influence on the initial stiffness of the structure from the change in fill density and the related change in the stiffness of the fill. And by comparing the dissipation at the same dolphin displacement it was found that the denser fill increase the dissipation by 16% for the 20m dolphin and by 23% for the 30m dolphin. The larger sensitivity for the large dolphin is explained by a larger contribution to the dissipation from strain in the fill. In low level impacts the dynamic force-response is up to 26~58% larger than the quasi-static and the dissipation response is showed larger in small displacement. Hence, it is concluded conservative to use the quasi-static response characteristics in the approximation of the response, and it is further concluded that the dolphin resistance to low level impacts is demonstrated to be equivalent and even superior to the high level impacts.

Acknowledgement

Supported by : 충북대학교

References

  1. 대한토목학회, 교량설계핵심기술연구단(2008), 도로교설계기준해설, 기문당, pp. 63-64.
  2. 김주영, 김정태, 류연선, 나원배, 박재형(2005), 선박충돌시 교각 및 충돌 방지 시스템의 거동해석, 한국해양과학기술협의회공동학술대회, pp. 1728-1733.
  3. 서석구, 이석용, 양병홍, 홍석주(2007), 섬식 충돌보호공의 계획과 설계, 대한토목학회지, Vol. 55, No. 8, pp. 39-49.
  4. 이계희, 홍현석, 백종균(2003), 강재 충돌 방호공의 선박충돌해석, 2003년도 학술발표회 논문집, 한국전산구조공학회, pp. 71-78.
  5. 이성로, 이계희, 이완수(2004a), 교량의 선박충돌 에너지산정, 대한토목학회논문집, Vol. 24, No. 5A, pp. 951-960.
  6. 이성로, 이계희, 이완수(2004b), 선박의 교각충돌에 대한 해석, 2004년도 학술발표회 논문집, 한국구조물진단유지관리공학회, Vol. 8, No. 1, pp. 81-86.
  7. 이처근(2001), 원심 및 수치모델링에 의한 화강토 지반상 Diaphragm Wall의 거동, 박사학위논문, 충북대학교, pp. 70-93.
  8. AASHTO(1991), Guide Specification and Commentary for Vessel Collision Design of Highway Bridges, American Association of State Highway and Transportation Officials, Washington, D. C., pp. 1-190.
  9. AASHTO(1994), LRFD Bridge Design Specifications and Commentary, American Association of State Highway and Transportation Officials, Washington, D. C., pp. 1-244.
  10. Chen, D.(2000), Simplified Ship Collision Model, Master Thesis, Virginia Polytechnic Institute and State University, pp. 1-99.
  11. Gucma, L.(2009), Methods of Ship-bridge Collision Safety Evaluation, R&RATA #2(13) Part 1, Vol. 2, pp. 50-63.
  12. Knott, M.A. and Larsen, O.D.(1990), Guide Specification and Commentary for Vessel Collision Design of Highway Bridges, No. FHWA-RD-91-006, US Department of Transportation, Federal Highway Bridges, US Department of Transportation, Federal Highway Adminstration, U.S.A., pp. 1-190.
  13. March, K. J. and Cambell, J. D.(1963), The Effect of Strain rate on the Post Yield Flow of Mild Steel, Journal of Mechanics and Physics of Solids, Vol. 11, No. 1, pp. 49-63. https://doi.org/10.1016/0022-5096(63)90007-3
  14. Pedersen, P. T., Valsgrad, S., Oisen, D. and Spangenberg, S. (1993), Ship Impacts: Bow Collisions, International Journal of Impact Engineering, Vol. 13, No. 2, pp. 163-187. https://doi.org/10.1016/0734-743X(93)90091-K
  15. Proske, D. and Curbach, M.(2003), Risk to Old Bridges due to Ship Impact on German Inland Waterways, Safety and Reliability, Bedford and Van Gelde, Balkema, Rotterdam, pp. 1263-1270.
  16. Wang, G., Ohtsubo, H. and Arita, K.(1998), Inner Dynamics of Side Collision to Bridge Piers, Gluver, H, Olsen, D., International Symposium on Advances in Ship Collision Analysis, pp. 53-60.